[Objective]To reconstruct the history of climate change and reveal climatic characteristics from 1947 to 2014 in Miyun mountainous area, based on stable carbon isotope (δ¹³C) of tree-ring in Pinus tabulaeformis.[Method]In this paper, tree-ring samples of Pinus tabulaeformis in Miyun mountain area were collected to analyze tree-ring δ¹³C. Moreover, we eliminated the effect of atmospheric CO₂ from original δ¹³C series and establish the de-trend series (DS) of tree-rings. Then, regression equations were established based on analysis of the correlation of δ¹³C DS combined with temperature and precipitation, and further reconstructed the temperature and precipitation histories from 1947 to 2014.[Results] From 1947 to 2014:tree-ring δ¹³C series had a downward trend with a big fluctuation from 1997 to 2014. A quadric curve trend was found in tree-ring DS. Tree-ring δ¹³C DS is extremely and positively correlated with July temperature (r=0.719 7,P<0.01). The average temperature of July from 1947 to 2014 were reconstructed with regression method. Results showed that the average temperature of July firstly declined and then increased since 1980 with an average of 25.67℃. The tree-ring δ¹³C DS was extremely and negatively correlated with summer precipitation (r=-0.696 7,P<0.01). Summer precipitation data from 1947 to 2014 were reconstructed with regression method. Results showed that the average summer precipitation was 450.3 mm. After 1980, summer precipitation fluctuated sharply with an evident declining trend.[Conclusion]The response of tree-rings δ¹³C in Pinus tabulaeformis to July temperature was extremely and positively significant. The tree-ring δ¹³C values were extremely and negatively influenced by summer precipitation. Overall, the climate in Miyun mountainous area showed a fluctuated warming and drying trend from 1947 to 2014.

[Objective] Environmental factors are the main factors influencing canopy water use. In this study, Qinghai spruce, a main tree species in Loess Plateau, was used as the research object, and the evapotranspiration characteristics were analyzed, in order to investigate the adaptability of different canopy conductance (g_c) models.[Method] In June 2013, the evapotranspiration of Qinghai spruce was monitored with Granier's thermal dissipation probe by a time step of 15 min. The quarter-hourly g_c was continuously simulated by the inversed Penman-Monteith model using the collected data by Granier's thermal dissipation probes. Accounting for the lag time, a multivariate linear model and six Jarvis models were used to simulate the relationships between g_c and three key meteorological parameters of saturated vapor pressure deficit (D), air temperature (T) and solar radiation (R). A cross-validation method was employed, that is, the data collected on odd days were used to calculate g_c, and the calculated results were verified by the data collected on even days.[Result] In the studied Qinghai spruce forest, canopy transpiration lagged meteorological factors by 15 minutes. Canopy transpiration (E_c) was a quadratic function of R(P<0.000 1), and g_c was an exponentially decreasing function of D and T (P<0.000 1). Although multivariate linear methods yielded slightly lower regression coefficients of g_c estimation (r²=0.9) than Jarvis methods (0.91 ≤ r² ≤ 0.92), they provided the best daily E_c estimation from the predicted g_c. Furthermore, all of the predicted g_c/E_c values were consistent with the measured g_c/E_c, indicating that all methods could predict g_c with sufficiently high accuracy.[Conclusion] R was the main driving force of E_c of the Qinghai spruce canopy. The 7 models all have high accuracy, but the Jarvis model has many patterns and complex applications. The undetermined coefficients of the some models can have infinite solutions which are quite different. However, the multivariate linear model is simple in form and high in precision, which is a better choice for simulating g_c.

[Objective] In this study, we investigated the changes of the phenotype, chloroplast ultrastructure and photosynthetic characteristics of Liriodendron sino-americanum under waterlogging stress, to reveal the response mechanism of L. sino-americanum in waterlogged stress and thereby provide a theoretical basis for promotion of cultivation and application in waterlogged districts.[Method] L.sino-americanum somatic embryo regeneration seedlings with 3-5 leaves were subjected to sterile waterlogging treatment for various durations (1d, 3d, 5d, 7d, and 2d recovery after 7days waterlogging), and the effects of the treatments on phenotype, chloroplast ultrastructure and photosynthetic characteristics were investigated.[Result] The results indicated that:1) The longer waterlogging treatment led to more severe damages to L.sino-americanum seedlings including curled and yellow leaves, or even leaves fell off from the base. However, the apical buds had no obvious changes, which could be due to the defense mechanism initiated by L.sino-americanum under waterlogging stress. 2) Waterlogging stress resulted in swelled chloroplasts and severe damages to the chloroplast ultrastructure of L.sino-americanum including degradation of chloroplast membrane system, loose and disordered arrangement of grana and stoma lamella, accumulation of starch grains, and osmiophilic granules density increased and and gathered together at the late stage of stress. 3) The net photosynthetic rate, stomatal conductance and transpiration rate were decreased whereas intercellular CO₂ concentration was increased slowly. The electron transport rate, photochemical quenching coefficient, photochemical efficiency and photochemical actual quantum yield in photosynthesizerⅡ showed a significant decline. The photosynthetic characteristics were partially restored after 2 days recovery treatment after 7d waterlogging stress. These data suggested that waterlogging stress caused serious damage in photosynthesizerⅡ activity center, and L.sino-americanum reduced gas exchanges by closing the stomata.[Conclusion] Taken together, waterlogging stress can cause the damages of chloroplast ultrastructure of L.sino-americanum, and then damage the photosynthesizerⅡ activity center, resulting in a decrease in leaf photosynthetic capacity and inhibition on growth and development of L.sino-americanum seedlings, but the seedlings may obtain to certain degree resistance under short-term waterlogging stress.

[Objective] This study investigated the characteristics of transpiration and the Tr/ET of the apple forests, and analyzed the relationship between transpiration of apple trees and environmental factors under different time scales, to provide a scientific basis for reducing the soil evaporation, controlling the transpiration and improving the efficiency of water use.[Method] This study was conducted in the Changwu Tableland, a typical representation of the Loess Plateau region. The thermal diffusion probe method was used to measure the sap flow of apple trees in 20a and 10a apple forests in 2015 at daily and monthly scales, and meteorological data were collected in an automatic meteorological observation station located at 50 m from the experimental plot, and at the same time, the soil moisture content and soil evaporation were determined.[Result] 1) On the day scale, there was a positive significant correlation between the transpiration of apple forests and air temperature (T_a) and VPD. However, the daily transpiration of the two apple forests declined when VPD> 1kPa. The monthly transpiration was also significantly correlated to air temperature (T_a) and VPD. 2) On the month scale, the experiment can be divided into three periods according to the soil water storage and consumption:the rapid soil moisture consumption period (May-Jul.), the soil moisture stable period (Aug.) and the slow soil moisture consumption period (Sep.-Oct.). Water consumption by transpiration of the 10-year-old apple forest mainly came from the soil layers of 0-300 cm, while the water consumption of the 20-year-old apple forest came from 0-600 cm. In the extremely dry month (Jul.), the water mainly came from the soil layers of 300-600 cm. 3) The Tr/ET of the 20-year-old apple forest was 29.25-67.51% and that of the 10-year-old apple forest was 36.44-62.06%. The Tr/ET of the different age apple forests showed the trend that increased first and then decreased. The Tr/ET of 20-year-old apple forest declined sharply after reaching a peak in August, while the 10-year-old apple forest declined sharply in September after a transition period.[Conclusion] With the increase of time scales, the number of environmental factors associated with the sap flow velocity was gradually reduced, but VPD was the dominant factor at each time scale. The water source of transpiration of the 10-year-old apple tree was mainly concentrated in the 0-300 cm soil layers, while that of the 20-year-old apple tree was from the 0-600 cm soil layers. In the extreme water deficit July, the more water came from 300-600 cm soil layers in the 20-year-old apple forest. After the end of August, some appropriate conservation measures on soil moisture should be taken to reduce evaporation for the 20-year-old apple forest, while the corresponding measures can be carried out in September for the 10-year-old forest. Those measures would provide a relatively sufficient soil moisture for healthy growth of apple trees in the next year.

[Objective] To determine the possibility to produce triploids by pollen chromosome doubling induced with high temperature exposure, and to produce new triploid germplasm to breed new varieties of Populus canescens with better resistance and serve for ecological environment protection.[Method] Based on the observation of male meiosis, pollen chromosome doubling induced by high temperature exposure to produce hybrid triploid was conducted using aceto-carmine staining and chromosome doubling technique in P. canescens.[Result] The results indicated that it took 5-6 days for pollen mother cells (PMCs) to complete meisois. Compared to other Populus species, no significant differences in process of meiosis was observed in P. canescens. However, significant asynchronism of male meiotic progress of PMCs in the same bud was observed. The top of PMCs developed faster than the basal of PMCs in the same male bud. However, the middle PMCs was the slowest ones. The optimum treatment combination to induce pollen chromosome doubling was to use 38 or 41℃ high temperature to treat male buds for 6 hours when the meiotic stages of PMCs were from diplotene to diakinesis. The highest frequency of 2n pollen is 58.03%. 911 seedlings were obtained by crossing the treatment combination with higher frequency of 2n pollen with female gametes of P. alba. Among all the progenies, 42 triploids were detected, and the highest triploid production rate was 10.71%. Correlation analysis between the frequency of 2n pollen and triploid production rate was carried out. Non-significant positive correlation was observed between the frequency of 2n pollen and triploid production rate (r=0.599, P=0.116), suggesting that increasing the frequency of 2n pollen could help increase the triploid production rate.[Conclusion] Though significant asynchronism of male meiotic progress of PMCs in the same bud was observed in P. canescens, 56.33% 2n pollen could be achieved when the PMCs were exposed to high temperature at diplotene to diakinesis. The highest triploid production rate was 10.71%. Our findings suggested that it was possible to produce triploid by induced pollen chromosome doubling by high temperature exposure and obtained triploid P. canescens for the first time.

[Objective] AP2/ERF (APETALA2/ethylene-responsive factor) is one of the largest transcription factors in plants and widely involved in biotic stresses and abiotic stresses. The aims were to study the expression characteristics and promoter sequence function of PwERF8 in Picea wilsonii and clarify the expression pattern in response to abiotic stress. The study would provide a basis for further understanding the regulation mechanism of stress resistance.[Method] The full coding sequence of PwERF8 was cloned from P. wilsonii by RACE-PCR technique. The promoter sequence of PwERF8 was cloned by genome walking. The cis-acting elements, BCP region and transcriptional start site were predicted by PlantCARE and BDGP online software. To characterize the function of promotor, the pBI121-PwERF8 promoter∷GUS was transferred into tobacco leaves by agrobacterium-mediated method. The PGBKT7-PwERF8 was transformed into AH109 yeast strain to verify its transcriptional activation activity. To investigate the subcellular location of PwERF8, the construct encoding 35S∷PwERF8-GFP fusion protein was transferred into Arabidopsis thaliana protoplast by PEG-mediated method. RT-qPCR was performed to analyze the tissue expression specificity and the dynamic expression of PwERF8 under abiotic stress.[Result] The full-length coding of PwERF8 was 1 190 bp containing a 765 bp open reading frame flanked and encoded 255 amino acids. It contains one AP2 domain consisting of 58 amino acids in the N-terminal and one EAR motif (DLNLPP) in the C-terminal. The tissue-specific expression analysis showed that PwERF8 were all expressed in stem, root, needle, pollen and seed, however, the expression level in pollen was the highest, followed by seed. Single cross of yeast showed no transcriptional activation activity of PwERF8 protein. The subcellular localization analysis showed that PwERF8 was mainly localized in the nucleus. The online analysis showed that the promoter sequence of PwERF8 contained cis-acting elements such as GA, ABA, JA and SA. Furthermore, GUS color reaction experiment showed that PwERF8 promoter sequences with cis elements could respond to GA, ABA, JA and SA hormones. The expression of PwERF8 under GA, ABA, MeJA and SA hormone treatments after 3 h, 6 h and 12 h were significantly higher than those in the control. The expression of PwERF8 under stress treatments showed that the expression of PwERF8 was induced by drought, 4℃ and 42℃, respectively, but not by the salt stress.[Conclusion] Picea wilsonii transcription factor PwERF8 is involved in the signaling pathways of GA, ABA, JA and SA hormones and extensively responds to abiotic stresses such as drought, temperature stress. It probably plays a major role in the nucleus as a transcriptional repressor.

[Objective] As an important component in plant cell wall, expansins are not only involved in most of the physiological process in plants, such as seed germination, vegetative organ development, fruit ripening and organ abscission but also involved in the process of stress resistance in plant. In this study, the promoter sequence of a expansin gene CpEXP1 was isolated from Chimonanthus praecox ‘Qingkousuxin’. The promoter activity study laid a theoretical foundation for exploring the molecular regulation mechanism of CpEXP1 gene during development in C. praecox.[Method] The promoter of the CpEXP1 gene was cloned by hiTAIL-PCR method. The cis-elements were analyzed by online bioinformatics tools. The promoter-reporter vector was constructed and introduced into tobacco by Agrobacterium-mediated method for transient-expression. Then the plant expression vector was transferred into Arabidopsis thaliana for further stable expression study.[Result] The regulative sequence(2 485 bp)of the expansin gene CpEXP1 promoter(GenBank Accession:MG452931) was cloned from genomic DNA of C. praecox. Bioinformatics analysis revealed that the promoter sequence contained basic cis-elements, such as TATA-box and CAAT-box and many elements involved in the plant tissue-specific expression and abiotic stress. The result of transient-expression showed that CpEXP1 gene promoter could drive the GUS report gene expressed in leaf dish of tobacco. Analysis of T3 transgenic plants with histochemical staining and GUS gene expression with the quantitative real-time PCR showed that strong GUS activity appeared in seed germination stage and almost no expression in cotyledon and tender leaves. There is a weak expression of GUS gene in root and flower in transgenic Arabidopsis. With the maturation and senescence of Arabidopsis leaf and flower, the strong GUS activity can be detected at the basal of petiole and carpopodium. GUS gene expression level of transgenic plants have increased with different treatments, including high temperature(42℃), low temperature(4℃)and salicylic acid(SA).[Conclusion] Based on the time-space specificity of CpEXP1 gene promoter activity in various organs during different development stages in transgenic Arabidopsis, we speculated that the CpEXP1 gene promoter would be closely related with seed germination,fruit expanding growth and leaf abscission. On the other side, GUS gene expression was induced by different abiotic stress treatments such as high temperature, low temperature and salicylic acid, which indicated that the CpEXP1 gene promoter may also play a role in abiotic stress resistance.

[Objective] A survey of diseases caused by the genus of Phytophthora were carried out in the subtropical forests of China. This study aimed at exploring the genetic diversity of Phytophthora and providing a theory basis for controlling the disease caused by Phytophthora.[Method] The healthy leaves were used to bait Phytophthora isolates from stream water.The symptomatic leaf tissues were isolated and Phytophthora was preliminarily determined based on its hyphal branching structure under a microscope,then ITS and β-tubulin gene of strains were amplified with PCR and sequenced.The spliced sequence was used for phylogenetic analysis with MAFFT 7,PAUP 4 beta10,MrBayes 3.2.6 and PhyML 3 software.[Result]Forty-six isolates of Phytophthora were obtained, and their morphological characteristics were consistent with P. intercalaris, a new record species in China. All isolates produced ITS amplicons of 847 to 849 bp in size, which differed from each other in one to three positions. These sequences had identity from 99.29% to 99.53% with the reference sequences of P. intercalaris type culture (KT163268). All the β-tubulin amplicons were 882 bp, which shared 99.43% to 99.66% identity with reference sequences of P. intercalaris (KT163336). Phylogenetic analysis showed that the tested strains were clustered with P. intercalaris with a high bootstrap support value (100%). This study not only increased the number of P. intercalaris isolates, but also expanded the distribution range of P. intercalaris, and enriched the number of Phytophthora species in China as well.[Conclusion]The result of gene sequence analysis showed that there was high sequence consistency among isolates of P. intercalaris from different regions, but there were variations in the base site, which formed different gene types. The present study provides a theoretical basis for the further development of the epidemiology and control strategy for the tree blight diseases.

[Objective]In order to provide valuable information and suggestion on controlling Batocera horsfield, an important wood-borer pest, geostatistical spatial distribution of its egg, larva, adult or pupa were studied, when it attacked and damaged severely different poplar forests.[Method]Population size of B. horsfieldi egg, larva, adult or pupa were determined, by the investigating of incisions, frass holes and emergence holes of sampling trees at four forest type plots, including highway forest, patch forest, ditch forest and village forest. Spatial distribution patterns of egg, larva, adult or pupa of B. horsfieldi in different poplar forest types, were analyzed with geostatistical method.[Result]The semivariogram curve models of egg, larva, adult (pupa) of B. horsfieldi in different poplar forest types were as follows. The highway forests were all spherical models. The patch forests were all exponential models. The ditch forests are exponential models, spherical model and gauss model. The village forests were spherical models, exponential model and exponential model. Therefore, it was found that the spatial distribution patterns of the all the models were aggregated, although their models were different in different poplar forest types. The semivariogram curve models and models parameters of B. horsfieldi population in different poplar forest types were obviously different, because poplar forest types effected their population size and distribution. The range(a), nugget(C₀), sill (C₀+C) of egg, larva and adult (pupa) in patch forest plots were less than those of other three type forest plots.[Conclusion]The spatial distribution patterns of B. horsfieldi egg, larva, adult or pupa were all aggregated, when it damaged poplar trees in highway forest, patch forest, ditch forest and village forest respectively. In short, the spatial patters of their different developmental stages in different poplar forest types were all aggregated distribution. There was little correlation between the aggregated behavior and forest types of B. horsfieldi attacking. But forest types effected semivariogram curve models and models parameters of B. horsfieldi population in different poplar forest types.

[Objective] In this study, the natural enemies of the invasive pest Sirex noctilio (Hymenoptera:Siricidae) in China were identified,and the dominant parasitoids and their biology were determined to provide a basis for determining the optimal control period and biological control agents.[Method] The sampling sites were set in the Scotch pine stands infested by Sirex noctilio, and continuous field surveys were conducted in combined with laboratory rearing and observation in this study from 2015 to 2016.[Result] 1) The result showed that there were 3 types of natural enemies in Sirex noctilio, including parasitic wasps, pathogenic fungi and nematode. Of which there were 5 species of parasitic wasps:Rhyssa persuasoria persuasoria (Hymenoptera:Ichneumonidae), Ibalia leucospoides leucospoides (Hochenwarth), Ibalia rufipes drewseni Borries (Hymenoptera:Ibaliidae) and Pseudorhyssa nigricornis (Ratzeburg) (Hymenoptera:Ichneumonidae), 2 species of pathogenic fungi (Trichoderma atroviride Bissett and Trichoderma viride Persoon) and a nematode Deladenus siricidicola Bedding. 2) Rhyssa persuasoria persuasoria was determined as a dominant species of parasitoid, and its natural parasitism rate was 9.3%. The wasp had one generation a year, ovipositing in young larvae or older instar larvae of its host. It was primary monoparasites and overwintered as larvae within tunnels of Sirex noctilio. Its pupal stage was 10-15 d and the peak period of the adult emergence was in the early May. The adult had a longer life span. It had a strong ability of rainwash resistance and a good adaptability to natural environment. 3) Through anatomical observation of Sirex noctilio under the microscope, the infection rate of larvae of Sirex noctilio caused by nematode was 32.1%, and the infection rate of the adult was up to 70.9%.[Conclusion]The above-mentioned result showed that Rhyssa persuasoria persuasoria (L). was an important insect species of natural enemies for control Sirex noctilio and the most appropriate control period was larvae or older instar larvae (i.e. from late April to middle May in local time). Moreover, based on the parasitism rate and effect, D. siricidicola Bedding would be considered the primary biological control means, which should futher focus on the study and utilization in biological control of the pest.

[Objective] The effects of isothermal crystallization on the crystallinity, physical and mechanical properties of wood fiber (WF)/poly(lactic acid) (PLA) composites were investigated in this study, which provides the basis for improving the processing and application of PLA composites.[Method] The pure PLA panels and WF/PLA composites were prepared by hot-pressing and followed by a cooling process for isothermal crystallization at different temperatures (90, 100, 110, 120 and 130℃). The crystallinity and melting characteristics of pure PLA panels and WF/PLA composites were characterized by differential scanning calorimeter(DSC), and the isothermal crystallization process was observed by polarizing microscope(POM), then the effects of isothermal crystallization process on the crystallization properties of PLA were analyzed by combining with crystalline morphology. Moreover, the effects of microstructures and molecular weights on the mechanical properties were also investigated by scanning electron microscope(SEM) and gel chromatography(GPC).[Result] The results showed that the crystallinity of pure PLA panels and composites increased from 4.6% and 15.1% to 24.8% and 40.5%, respectively. Compared with the fracture surfaces of virgin WF/PLA composite, it was obvious to seen that wood fibers were pulled out from the matrix of WF/PLA after isothermal crystallization at 90, 100 and 110℃, indicating that the isothermal crystallization make a poor effect on interfacial bonding. The molecular weight of PLA decreased after the isothermal crystallization. According to the result of POM, it could be seen that the crystal size increased with increasing isothermal crystallization temperatures. After isothermal crystallization, the bending properties and tensile strength of pure PLA panels were improved. Moreover, the flexural modulus of WF/PLA also increased with isothermal temperatures, however, the flexural and tensile strength reduced to some extent.[Conclusion] The crystallinities of pure PLA panels and WF/PLA composites increased gradually after the isothermal crystallization, moreover, the crystallinity of the WF/composites showed a larger improvement due to the ability of promoting nucleation of wood fiber. The lower of the isothermal crystallization temperature, the smaller of the crystal size was. The higher of the isothermal crystallization temperature, the larger of the crystal size was. The bending and tensile strength of pure PLA panels were improved after isothermal crystallization. However, the mechanical properties of WF/PLA showed irregular rules. Isothermal crystallization exhibited different influences on the mechanical properties of pure PLA panels and its composites, which maybe relate to the poor interfacial bonding.

[Objective]The present research is for further understanding the structure characteristics and thermal properties of soluble lignin and insoluble lignin of moso bamboo (Phyllostachys edulis) by low alkaline charge kraft pulping to provide theoretical reference to the application of lignin from bamboo.[Method]The moso bamboo was pretreated by kraft pulping with effective alkalinity of 12%. To isolate the soluble lignins, black liquor was acidified to precipitate black liquor lignin, namely kraft lignin (KL). Enzymatic hydrolysis was performed on the solid pulp to obtain residual insoluble lignin in pulp, namely enzymatic hydrolysis lignin (EHL). Organic solvent purification was utilized on the lignin isolates to ensure the absence of unbound carbohydrates. The molecular weights of KL and EHL were determined by gel permeation chromatography (GPC). ³¹P nuclear magnetic resonance (NMR) and the combination of ¹³C and 2D-HSQC NMR were performed to quantify the amount and variety of hydroxyl functional groups and inter-lignin linkages respectively. Thermal properties of KL and EHL were measured by thermogravimetric analysis (TGA) to determine the thermostability and differential scanning calorimetry (DSC) for estimating glass transition temperature.[Result]The approximate values of molecular weights of KL and EHL obtained by GPC were 5 414 g·mol^-1 and 7 673 g·mol^-1 respectively. Hydroxyl quantification from ³¹P NMR indicated a greater amount of aliphatic hydroxyl in EHL (4.87/100 C₉) than in KL (3.13/100 C₉). As for phenolic hydroxyl, an opposite trend was shown, 1.58/100 C₉ for EHL and 3.09/100 C₉ for KL. Quantification of inter-lignin linkages through the combination of 2D-HSQC and ¹³C NMR spectra showed the inter-lignin linkages in EHL were 30.85/100 C₉ for β-O-4, 7.43/100 C₉ for β-β, 2.40/100 C₉ for β-5, and 0.19/100 C₉ for β-1. KL, bearing less inter-lignin linkages, was found to contain 11.75/100 C₉ of β-O-4, 2.35/100 C₉ of β-β, 0.71/100 C₉ of β-5, and 0.09/100 C₉ of β-1. The thermal property measurement under heating showed that the greatest weight losses with EHL and KL occurred at 361℃ and 339℃ respectively, and the glass transition temperatures were 162℃ and 135℃ respectively.[Conclusion] Low alkaline charge kraft pulping of moso bamboo yields liquor-soluble lignin which has lower molecular weight and less inter-lignin linkage than the residual lignin in pulp. Phenolic hydroxyl groups have the greater functionality in the black liquor lignin, than aliphatic hydroxyl groups in the residual lignin in pulp. The black liquor lignin has greater advantage for the preparation of the lignin-polymer thermoplastic material than the residual lignin in the pulped bamboo, due to lower thermostability and glass transition temperature.

[Objective] The present work is for studying the preparation of adsorbent with modified tannin to provide technical basis for the application of natural tannin in the treatment of heavy metal ions pollution.[Method]With bayberry tannin (BT) and acacia mangium tannin (AMT) as raw material, the formaldehyde reacted with condensed tannin to form hydroxyl methylated tannin under alkaline conditions. Then the amide group of polyacrylamide (PAM), as nucleophilic reagent, reacted with hydroxyl methylated tannin to prepare bayberry tannin adsorbent PBT and acacia mangium tannin absorbent PAMT, respectively. The physicochemical properties of tannin before and after modification and adsorption of Pb(Ⅱ) and Cu(Ⅱ) were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and infrared spectroscopy(FTIR). The adsorption performances of Pb(Ⅱ) and Cu(Ⅱ) were also investigated.[Result]The results showed that the crosslinking reaction was occurred with the modification of BT and AMT, leading to increased particle size, but no significant change in the microscopic surface. The maximum adsorption capacities of 49.75 and 142.86 mg·g^-1 were obtained for Cu(Ⅱ)and Pb(Ⅱ)on PBT respectively, and the maximum adsorption capacities of 34.16 and 115.61 mg·g^-1 were obtained for Cu(Ⅱ)and Pb(Ⅱ)on PAMT, respectively.[Conclusion]The PAM modified tannin adsorbents have good stability and stronger adsorption capacity. The equilibrium adsorption capacities of Pb (Ⅱ) and Cu (Ⅱ) were higher than those of BT, AMT and PAM, indicating that the PAM modified biomass adsorbent has bright prospect.

Moisture in wood gives serious effect on wood utilization and processing, and moisture content of wood should therefore be adjusted to an appropriate range through drying. Conventional drying can be improved due to great energy consumption and considerable drying defects, while the industrialization of new energy-saving drying technologies such as heat pump drying and solar drying are far from perfection. Considering the source of water in wood and the physiological properties of water in trees, the present work discusses a new drying theory and technology for living trees, namely, physiological drying based on transpiration. The basic theory of physiological drying for living trees from the viewpoint of water and plant physiology are expounded. Three possible evaporation locations summarized from the researches on water evaporation in leaves are presented as:all the mesophyll cells and epidermis exposing into the inner air spaces, the most mesophyll cells and epidermal cells around the substomatal cavity nearby the stomatal pore, and other mesophyll and epidermal cells around the substomatal cavity. By analyzing the research on water transmission theory in plant, three potential water transport ways inner leaves are presented as:the symplastic pathway via plasmodesmata, the transcellular pathway by aquaporin and the apoplastic pathway through the non-suberized cell wall. Studies on the cohesion-tension theory(CT/CTT)widely used to explain the dynamics of long-distance water transport in xylem with the current arguments and some rising theories, such as the multi-force theory and watergate theory are reported. In addition, the common phenomenon of cavitation and embolism and its recover mechanics during the process of long-distance water ascent is discussed. On this basis, 4 focal points for further studies are suggested as:1) To explore the relationship between stomatal transpiration and cuticular transpiration when the trees were subjected to severe water stress in the process of physiological drying; 2) To locate the water evaporation points within leaves; 3) To understand the effect of the microstructure of pits on the process of long-distance water transportation in xylem and on the forming and recovering processs of the cavitation and embolism; 4) To reveal the mechanism of the formation and recovery of cavitation and embolism in physiological drying, and their effects on the long-distance water transportation.

Nanocellulose is a green nanomaterial obtained from natural plants, several marine animals and exceptional microbes. As the results of its unique network structure, outstanding mechanical properties and high specific surface area, nanocellulose can be effectively compounded via layer-by-layer self-assembling, in-situ chemical polymerization and electrochemical deposition with various nanoparticles such as metal oxides, conductive polymers, and two-dimension nanomaterials,to form different nanocellulose-based porous film material and electroconductive composites. These nanocomposites have great application prospects in the separator and electrode materials for mental ion battery and supercapacitor. Based on the differences in source materials, preparation methods, and fiber morphology, nanocellulose is divideed into cellulose nanocrystal, cellulose nanofibril, bacterial nanocelluloe, and electrospun cellulose, and the former three are widely used for energy storage materials. Naturally, nanocellulose is frequently mixed with water and maintains in the stable colloidal state. After the loss of water, the nanocellulose mixture is able to form self-assembled nanocellulose film with outstanding mechanical properties and thermal stability. The film exhibits good ability of moisturizing in electrolyte solution and smoothness for free ion and electron transfer as a promising choice for separator in green energy storage. Due to the advantages of sufficient active groups, unique network and easiness to form film, nanocellulose, incorporating with other conductive active ingredients such as carbon nanomaterials, metal oxide, and conductive polymers, plays significant role of skeleton material in the preparation of electrode for energy storage. The nanocellulose can also be directly carbonized for electrode materials, and its electrochemical performance is closely related to the degree of graphitization. To improve the electrochemical performance, the carbonized nanocellulose is often further treated by N-and C-doping. Currently, the major nanocellulose based electrode materials include nano-cellulose carbon fiber materials, two-dimension nanomaterials, conductive polymer materials and multi-component materials. Although nanocelluse poses incomparable merits and perspective future in the application to green energy storage, it still faces huge challenges in the incorporation pattern between nanocellulose and electrode active material, poor interfacial compatibility and microstructure regulation. It is suggested that the future work would focus on the tough problems of maximizing the size effect in nanometer and instinctive network structure, building more elaborate nano-system and designing energy storage device with higher conversion efficiency. This paper briefly introduces varieties and properties of nanocellulose, highlights its present application status in separator materials and novel electrode materials, and predicts its future development.

With deeper understanding of resource crisis and environmental pollution,the development of low-priced, renewable and biodegradable natural polymers is drawing great attention. Lignin is the second-largest amount natural high molecular material, only next to cellulose, and is the only non-fossil natural resource, which can provide renewable aryl compounds. The research on the molecular structure of lignin is therefore arousing more concern. The main constitutive monomeric units of lignin are syringyl (S), guaiacyl (G) and p-hydroxyphenyl (H). Lignin can not only strengthen cell walls but also waterproof and protect them against microorganisms. Lignin and hemicelluloses are covalently linked forming lignin-carbohydrate, which fills the voids between microfibrils, and further creats a highly complex 3-D hierarchy structure as a natural biomass recalcitrance against degradation. In biomass refinery, the distribution of lignin directly affects the biomass conversion efficiency. Therefore, in situ study on the molecular structure, micro-distribution and solution pattern of lignin at cellular level is of great significance. In traditional wet-chemistry, milled wood lignin and Klason lignin are commonly used for quantitative and qualitative investigation of the lignin molecular structure. However, the physical or chemical pretreatments required will inevitably disrupted the native-state molecular structure of lignin samples. Although the general optical and electronic microscopy can provide the information on lignin micro-distribution in plant cell walls, complicated staining and embedding are needed for sample preparation. By comparison, Raman spectroscopy with its features of non-destruction, rapidity, high resolution and high sensitivity shows unique advantage in the studies on the macromolecular structure and topochemistry. In the present review, Raman band assignments of G, S, H lignin units and biomass materials are summarized, and the factors influencing lignin Raman spectra are briefly introduced. Progress of the application of Raman spectroscopy to lignin micro-distribution and cellular level dissolution is discussed in detail. The prospect of Raman spectroscopy in the research on lignin is discussed with new ideas and methods for the plant physiology and biomass refinery, especially the design of highly-efficient biomass pretreatment.

Nowadays, it is difficult for the naturally-growing wood to meet the growing demand in China. Thus, plantation wood plays a more and more important role in alleviating the contradiction between supply and demand. Plantation area in China ranks first in the world, but the quality of wood is poor, which limits its application. Therefore, it is becoming more and more important to cultivate good quality plantation wood. Genetic engineering can from the fountainhead improve the quality of the plantation wood in the limited forestland. In order to provide reference for further research and application of genetic engineering to the quality of plantation wood, this paper reviewed the effects of genetic engineering on wood chemistry, structure and physical & mechanical properties of plantation wood. For wood chemistry, the effects of genetic engineering are mainly on the changes in lignin content, proportion of lignin monomer, and the contents of cellulose, hemicellulose and other chemical compositions. The research on reducing lignin content achieved the most rapid development. For wood structure, the effects are mainly on the changes of cell morphology and microfibril orientation, and therefore the improvement of the quality of fibers, and the quality of pulp is expected. For wood physical and mechanical properties, the effects on density, shrinkage, and strength with many target genes of obvious impacts are reported. At present, genetic engineering improvement of plantation wood quality is still in the primary stage and there are still some problems to be solved. 1) The cell wall formation of transgenic plants is under precise regulation of time and space. Therefore, the impacts of time and environmental factors on the transgenic plants, the stability of genetic engineering improving wood quality, and the cultivation environment and measures that conducive to the stable expression of target genes should be deeply studied. 2) Genetic engineering can improve wood properties, but the degree of improvement differs. Thus, it is necessary to find the genes that can be stably inherited and the methods to improve the expression level of target genes. 3) The fundamental research on the genetic improvement of wood properties is far from sufficiency. The variation of the improvements needs to be further studied, more target genes that can make stable improvement need to be found and a complete and reliable basic database needs to be established.

The relationship between tree-width of Tetracentron sinense and climate factors in the humid evergreen broad-leaved forest in the middle Ailao Mountains was studied in order to explore the potential for reconstructing climate change in the past and to provide a theoretical basis for modelling species distribution and conservation of T. sinense in the context of global climate change.[Methods]Increment cores of T. sinense were collected by increment borer, and tree ring-width was measured with standard dendrochronological techniques. Each tree-ring measurement was assigned to the year of its formation with cross-dating techniques, and then tree-ring series were detrended with negative exponential curve and cubic spline function. The resulting standard chronology was correlated with monthly climatic data from Jingdong meteorological station.[Results] Analysis of tree ring-width chronology and climate factors showed that the radial growth of T. sinense was significantly correlated with mean temperature and extreme high temperature of February and June in the year (P<0.05). Moreover, ring-width chronology showed significant positive correlation with the number of hours of sunlight (P<0.05), but negative correlation with relative humidity of February and March (P<0.01). Our study demonstrated that multiple climatic factors influenced the radial growth, and the climatic conditions during the early growing season is crucial for the growth of T. sinense.[Conclusion] This study showed that T. sinense in the warm and humid subtropical forests produce distinct and cross-datable annual growth rings. Tree ring-width chronology of T. sinense can reveal considerable climate information, which has high potential for reconstructing past climate change in the study area.

[Objective] Geo-information TUPU can express spatial structure feature and temporal dynamics function. With this theory and method, we can construct wetland landscape change TUPU, and analyze the characteristics and laws of the study area, to provide decision support for the rational use and sustainable development of ecological environment.[Method] In this paper, the research is conducted based on the geo-information TUPU analytic method. By using the ENVI software to do supervised classification and ArcGIS software to do data format conversion and map algebra, the authors have compounded a series of varying TUPU of the wetland landscape by using spatial data covering three periods(1987, 1999 and 2015)in the Shenzhen Bay. We can comprehend the changes of wetland landscape in the Shenzhen Bay.[Result] The result shows that great changes have taken place on the wetland landscape in this bay during the past 26 years. 1) From the table which was TUPU unit order of wetland landscape change from 1987 to 1999 in the Shenzhen Bay, water area and base around the pond were declining most and significantly. The area of water being changed to tidal flats was 257.22 hm² and 12.9% of all changes in the area. The area of bare land being changed to built-up was 192.69 hm² and 9.6% of all changes in the area. Both tow landscapes were mainly in the northwest and northeast of the Shenzhen Bay. From the table which was conversion matrix of wetland landscape from 1987 to 1999 in the Shenzhen Bay, the increasing area of built-up area and bare land were 573.66 hm² and 296.01 hm², and the rate of change were 148.34% and 133.27%, which mainly became from base around the pond, water area and tidal flats and so on. 2) From the table which was TUPU unit order of wetland landscape change from 1999 to 2015 in the Shenzhen Bay, tidal flats, water area and bare land were declining significantly. The tidal flats became water area and water area became built-up area were most obvious, their change area both were about 407 hm² and 18.9% of all changes in the area. Secondary, the area of bare land became built-up area was 357 hm² and 16.6% of all changes in the area. These changes were mainly located in the Futian Mangrove Nature Reserve, Nanyou Area and Shenzhen Overseas Chinese Town(OCT)Area and other places. From the table which was conversion matrix of wetland landscape from 1999 to 2015 in the Shenzhen Bay, the increasing area of mangrove and green land were 59.4 hm² and 371.25 hm², and the rate of change were 80.88% and 92.99%. Mangrove mainly became from built-up areas, base around the pond and green land, while green land mainly became from built-up area, water area and bare land. 3) From 1987 to 2015, the arising area of built-up area, bare land, green land and mangrove were obvious. The most of increasing TUPU units was built-up area, which area was 1 471 hm² and 55.2% of the total area of arising. The area of other landscape types had decreased such as tidal flats, water area, and base around the pond. Totally, the area of transfer was 2 104.65 hm² and 79.00% of the total area of declining. The increase parts of mangrove were two times about the stable part, meaning the area of mangrove was increasing faster, which was distributed at Futian Mangrove Nature Reserve in Shenzhen Bay.[Conclusion] Geo-information TUPU method has been adopted to form the maps like changing, arising and declining, which contain various landscape types of change, increase or decrease. It is more conducive to explore the cause of the landscape change, process and predict the future trends.